1. Field of the Invention
The present invention relates to an inflator for supplying inflation gas to an airbag of airbag device for automobile which is used in an inserted state in the airbag.
2. Description of Related Art
Japanese Patent Laid-Open No. 2001-171468 discloses an inflator for a side impact airbag device mountable on a vehicle seat. The inflator is inserted within an airbag for supplying the airbag with inflation gas. The inflator includes a substantially cylindrical body for generating inflation gas, and a substantially tubular retainer made of sheet metal and mounted around the body for holding the body. The retainer includes a mounting means for mounting the airbag to a predetermined mounting position.
U.S. Pat. No. 5,687,988 discloses an inflator which is provided in an end face of a cylindrical body thereof with a flat mounting stud. A retainer made of sheet metal for holding the body is formed into a half-pipe shape which is open upward for supplying inflation gas. One of two axial ends of the retainer is provided with an end wall, and this end wall includes a slot for receiving the mounting stud. Adjacent to an open end opposing to the end wall having the slot is an arm which is plastically deformed to clamp the inflator body like a belt. When the inflator body is held by the retainer, the mounting stud of the body is inserted into the slot of the retainer, and the arm is deformed to belt-fasten the body. Thus both ends of the body is held by the retainer by the mounting stud fitted in the slot and the arm abutting against a circumference of the body, so that the inflator body is prevented from lifting out toward the gas supplying opening. The arm contacting the circumference of the inflator body prevents the body from sliding out from the open end side of the retainer.
In the inflator in the former reference, the inflator body is held by the retainer by fastening two fastening portions both of which are located in the vicinity of an axial center of the retainer. The inflator is put in the airbag in that state, and the airbag is folded to assemble an airbag device. When the airbag is folded, accordingly, the work has to be done in an environment considering malfunction of the inflator inserted in the airbag, which complicates the folding work of the airbag.
It might be possible to insert the inflator in the airbag after the folding work of the airbag. However, the mounting means such as bolts for mounting the airbag to the mounting position are protruded from the retainer of the inflator, and the mounting means obstruct insertion of the inflator in the airbag after the folding work of the airbag.
It also might be possible to insert the retainer only in the airbag firstly, and then set the inflator body in the retainer after the folding work of the airbag. However, the fastening portions of the conventional retainer are located in axial center. In the foregoing processes, the fastening portions arranged inside the folded airbag have to be fastened from outside of the airbag, which may damage the airbag.
As to the inflator in the latter reference, it might be possible to insert the retainer only in the airbag such that the arm of the retainer is located out of the airbag, and then to fold the airbag and set the inflator body in the retainer by inserting the mounting stud in the slot of the retainer. Then the arm is fastened for the retainer to hold the body. With this arrangement, however, it is difficult to insert the mounting stud into the slot located inside the airbag, since the slot is not visible. Therefore, the assembling work of the inflator is not easy, either.